Oops, it doesn't look like 'concert concert day' is a national day..

Other days

aloxolt

Aloxolt Day
comfy

Comfy Day
healing

Healing Day
book

Book Day
youth

Youth Day
lash

Lash Day
nail polish

Nail Polish Day
frozen yogurt

Frozen Yogurt Day
ride the wind

Ride The Wind Day
offer

Offer Day